RIGA, August 12./ITAR-TASS/. Russian photojournalist Andrei Stenin who went missing in Ukraine last week might have been arrested by the Ukrainian security service, an adviser to the Ukrainian interior minister said on Tuesday.

“As far as I know he has been arrested by our security service,” Anton Gerashchenko told Latvian media.

When asked if Stenin was being held by the Ukrainian security service, Gerashchenko said he had no collaborating documents but thought so.

Stenin went missing in the embattled Ukrainian south-eastern region earlier this week. One of Russia’s largest state-run news agencies Rossiya Segodnya (formerly RIA Novosti) said it had last heard from him on August 5.

The journalist went missing during a business trip to the south-east of Ukraine where he was making reports from Donetsk, Sloviansk and other cities and towns. Contact with him was lost on August 5.

For a week the Ukrainian authorities ignored constant inquiries and appeals from the Russian Embassy in Ukraine, the Organisation for Security and Cooperation in Europe (OSCE) and the International Federation of Journalists, and the European Union’s concerns.

The Ukrainian National Security Service kept silent about the journalist’s whereabouts and denied that it was holding any members of Russian mass media.

The charges brought against Stenin are “artificial and ridiculous”, Rossiya Segodnya Director-General Dmitry Kiselev said.

“The good news is that Andrei is alive. The bad news is that the Ukrainian authorities confirmed they were keeping him under arrest only a week afterwards. Apparently they needed a whole week to concoct a case against him,” Kiselev said.

Gerashchenko said earlier that Stenin had been arrested for “aiding, abetting and glorifying terrorism”.

OSCE Representative on Freedom of the Media Dunja Mijatovic has expressed concern about reports that Stenin had gone missing in eastern Ukraine.

“I call for Stenin’s immediate release,” Mijatovic said. “This dangerous practice of detaining and abducting media workers is unacceptable and must end,” Mijatovic said.

“I call on those responsible to stop targeting journalists for carrying out their work,” she said.

Several government agencies are working to bring Stenin from Ukraine back home, Russian presidential spokesman Dmitry Peskov said.

“The relevant agencies are taking measures to bring the journalist back home because the life of any our citizen, including journalists’, is the top priority in such situations of course,” he said.

Safety of journalists working in Ukraine’s war-torn southeastern regions repeatedly raised international concerns, particularly following a series killings of Russian and international journalists over the two months.